KR20220124822A - Method of fastening second object to first object - Google Patents

Abstract

According to one aspect of the present invention, there is provided a method of securing a second object to a fiber composite part comprising a structure of fibers embedded in a base material, the method comprising the steps of:
- providing a fiber composite part comprising an attachment surface, wherein a portion of the structure of fibers is exposed at the attachment surface;
- providing a second object;
- placing a second object against the fiber composite part with the resin in a flowable state between the attachment surface and the connector;
- pressing the second object and the fiber composite part against each other causing mechanical vibrations to act on the second object or the fiber composite part or both, thereby causing the resin to penetrate into the exposed structure of the fibers and the resin to cross activating to bind;
- whereby the resin, after cross-linking, fixes the second object to the fiber composite part.

Description

Method of fixing a second object to a first object, a kit of parts and fasteners for performing the same

The present invention relates to mechanical engineering and construction, particularly mechanical construction, for example automotive engineering, aircraft construction, rolling stock construction, shipbuilding, mechanical construction (manufacturing), It relates to the field of construction industry, toy construction, etc. (for example automotive engineering, aircraft construction, railcar construction, shipbuilding, machine construction, building industry, toy construction etc.). In particular, the invention relates to processes of fastening objects to each other.

Automotive, aerospace and other industries tend to move away from steel structures and instead use lightweight materials such as fiber composites, particularly carbon fiber reinforced polymers.

Fiber composite parts are manufactured with significant mechanical strength, under sufficiently high fiber content and average fiber length and under proper fiber orientation, but with additional objects such as connectors (dowels or the like) to them. its mechanical fixation is a challenge. Conventional riveting techniques are only suitable to a limited extent, in particular due to the small ductility of fiber composite materials. Also, since these connections require pre-drilling at the location where additional objects will be attached, positioning precision can be an issue, especially when several parts to be interconnected are attached to a fiber composite part. . Adhesive bonds can function well, but the problem is that the strength of the bond cannot be greater than the strength of the outermost layer and the strength of its attachment to the rest of the part. Also, curable adhesives always require some curing time for cross-linking. This will significantly increase the production time in the case of industrial production. To solve this problem, it has been proposed to use UV curable adhesives, which tend to cure faster than heat curable adhesives. However, they require connectors that are at least partially transparent to allow curing radiation to reach the curable adhesive. Also glue lines always suffer from sensitivity issues in terms of layer thickness and homogeneity of the adhesive distribution.

Materials other than fiber composites, including classic materials such as sheet metal, are increasingly used in lightweight versions, with correspondingly reduced mechanical strength. Thus - by means of a bore or the like - for example - fastenings which cause the material to weaken can increasingly be avoided.

In addition to UV curing, the prior art includes an approach to accelerate curing of adhesives by induction heating. However, this method is limited to bonds involving metallic parts. Also, induction heating is relatively unspecified and is not always an option due to constraints.

It would therefore be advantageous to provide a method for securing a further second object (eg a connector) to a first object, which overcomes the drawbacks of the prior art methods and forms a particularly strong reliable mechanical bond.

According to one aspect of the present invention, there is provided a method of securing a second object to a first object, the method comprising:

- providing a first object comprising an attachment surface;

- providing a second object;

- placing the second object relative to the first object, with a resin in a flowable state between the attachment surface and the second object, in which case the resin may be flowable from the beginning or at least flow by the effect of mechanical vibration may be possible, see below);

- mechanical vibration is generated while the resin is in contact with the first attachment surface and the second attachment surface, in particular while pressing the second object and the first object against each other, for example by means of a vibrating tool cause to act on the second object or the first object or both, thereby activating the resin to cross-link;

- The resin thereby fixes the second object to the first object after cross-linking.

As used herein, a "resin" is flowable (usually a viscous liquid) during at least one step of a process and covalent bonds formed between molecules of a resin and/or between molecules of a resin and other substances. Any material that can be permanently cured by For example, the resin may be a composition comprising a monomer or a plurality of monomers or a prepolymer in a flowable state that can be irreversibly changed into a polymer network by curing. have.

The fixing method according to the invention is characterized by the significant advantage that the first and second objects do not have to be weakened, since the bonding achieved is a purely adhesive bonding. In addition, especially if one of the objects is relatively thin - for example a sheet of metal - the method does not require a through opening to be formed in this object and therefore no measures have to be taken for sealing, electrical insulation, etc. characterized by advantages. In addition, the fastening is independent of the predefined structures, which makes it possible to compensate the tolerance mismatch (x-y position adjustment) in a fairly simple way.

It has been discovered by the inventors that mechanical vibration has a dual effect:

First, it allows the resin to be well distributed and fully wet/interpenetrate and, where applicable, to embed any structures on the attachment surface, thereby causing the resin to penetrate relatively deeply into these structures.

Second, mechanical vibration energy is mainly absorbed at the interface between the first and second objects and in the resin, thereby stimulating the curing process. More precisely, the resin was found to cure fairly efficiently and mostly at the interface. Given that a structure conforming to the attachment surface is provided, after the curing process, the resin is impregnated into the structure in addition to causing material bonding (ie adhesive bonding), and the structure may contain undercuts. This also results in a positive-fit connection. In fact, the curing process is accelerated at least an order of magnitude faster (using, for example, a two-component epoxy adhesive sold as a resin) compared to how fast it would be in the absence of ultrasonic vibrations. was found In general, a temperature increase of about 10° C. reduces the setting time by 50%. Indeed, short-term, ultrasonically induced temperature rises of about 50° C. or even 100° C. can be observed. In embodiments, the second object has a different structure than merely being planar at the attachment surface. Rather, the surface at the attachment surface may have distinct corrugations.

In particular, in embodiments the second object has a structure comprising undercuts. Thereby, the resin material which permeates the structure supported by the mechanical vibration will be fixed to the second object by the embossed fit joint after resolidification.

In embodiments, the first object comprises a fiber composite part comprising a structure of fibers embedded in a matrix material. In a group of embodiments, the fiber composite part will include a portion of the structure of fibers that is exposed, particularly at the attachment surface. The flowable resin material is then caused to permeate the structure of the fibers and possible voids in the material are caused to be avoided. Vibrations can also cause small motion of the fibers themselves, which helps to prevent spots from being impregnated at all. The structure of the exposed fibers will of course include the structures defining the undercut, whereby the above-mentioned embossed fit bond is achieved without requiring any additional measures.

In particular, the method may comprise causing a portion of the structure of fibers to be exposed, particularly by removing an outermost portion of the matrix.

Additionally or alternatively, if the first and/or second object has a material different from that of the fiber composite, the method comprises the surface roughness of the attachment surface of this object by methods known for this purpose, for example, for example. , mechanical wear, etching, and the like.

The resin used in these embodiments may have the same chemical composition as the base material of the fiber composite part, or may have a different composition.

The fiber composite part may itself constitute a first object to which the second object is fixed, or it may constitute a part of the first object which may include additional parts connected to the fiber composite part.

The fact that the structure of fibers is exposed to the attachment surface means that there is no homogeneous distribution of the matrix in the structure that completely embeds the fibers so that the resin material can flow between the fibers and/or into the structures formed below the fibers. .

To allow a portion of the structure of fibers to be exposed at the attachment surface, the method may include removing a substrate from the attachment surface to expose a portion of the structure of fibers prior to positioning the second object relative to the fiber composite part. .

Removal of such parent material may include any suitable material removal step. For example, this step may include sandblasting the attachment surface. Additionally or alternatively, the step may include chemical etching. Additionally or alternatively, this step may comprise grinding. In either case, the step may comprise a substep of providing a mask and causing only these portions of the surface to be exposed to material removal for which the structure of fibers is desired to be exposed.

As an alternative to the fiber composite part, also other materials are suitable materials for the first object. In groups of embodiments, such materials include particularly porous or otherwise inhomogeneous structures. An example of such a material is metallic foam. Additionally or alternatively, the first object may include surface irregularities in the attachment surface, the surface irregularities being in addition to or in an ablating process (mechanical, irradiated, chemical etching, etc.) It is caused by the (coating) process.

Similar to the exposed structure of fibers, the exposed structures in metallic or ceramic first objects may be grain boundaries exposed by chemical etching or formation of etch geometries.

In summary, the method may include providing a first object with a surface irregularity at an attachment surface, the surface irregularity being achieved by exposure of a portion of the structure of fibers, by uneven ablation, or by an additive process. can

Additionally or alternatively, the method may be, for example, by an additive or an ablation process (coating (eg priming), activating, etc.), for example to cause a sufficient surface concentration of OH groups or NH groups, for example. affecting the surface chemical properties of the first and/or second object.

In many of the embodiments described below, the first object is a fiber composite part. As such, the teaching also teaches metal foams, metal sheets or other metal parts (with or without a rough surface), porous or non-porous ceramic, porous or non-porous plastic, or any provided, for example, with surface unevenness. It also applies to other first objects, including the object of

A further advantage of the approach according to the invention is that the steps before contacting the second object with the first object do not require any precision in terms of positioning. The step of removing the parent material from the attachment surface (see below) or other surface preparation steps to expose a portion of the structure of fibers need only be roughly performed at the location where the attachment takes place. If accurate positioning of the second object relative to the fiber composite part is desired, this accuracy can be achieved by placing the second part directly in the required position. This is in contrast to approaches where, for example, a pre-drilled bore defines the relative position.

This can be easily integrated into industrial production processes where the equipment is used to position objects relative to each other, due to the speedy curing caused by the approach according to the invention, tolerance issues are eliminated This is especially advantageous given the fact that a balance could soon be reached.

The second object may be a connector and thereby serve to secure the further object to the first object. To this end, the second object may comprise a joining structure such as a helical part, a nut part, a part of a bayonet of a clip connector, or any other connecting structure. Alternatively, the second object may be a frame or housing or any other object to be secured to the first object.

In a group of embodiments, the second object comprises a second fiber composite—consisting of the same or a different composition as the fiber composite part, if applicable. In a subgroup of these embodiments, a portion of the structure of reinforcing fibers of the second object is exposed prior to the pressing step, whereby the resin is also exposed to the fibers of the second object with an effect similar to that described herein for a fiber composite part. seep into their structures.

In other embodiments, the second object, at the second attachment surface, comprises a different material than the fiber composite. It may be, for example, metallic, with or without a rough surface, and may have glass, ceramic, polymer-based materials, and the like. In a particular group of embodiments, the second object may include a rough and/or porous surface structure.

In embodiments, the second object comprises, for example, a distal facing second attachment surface, wherein the attachment of the first object by resin between the attachment surfaces in the step of positioning the second object relative to the first object disposed adjacent to a surface (the 'first attachment surface').

In embodiments, this second attachment surface is provided with at least one indentation (groove/channel, hole or the like), wherein the second attachment surface is attached to the first attachment surface. When pressed against, a cavity is formed, which can function as a buffer volume for excess resin material and guide resin flow. In particular, said at least one indentation can form, for example, a channel system of radially running channels that effectively guide the flow. More generally, the second attachment surface may be provided with at least one indentation or protrusion that results in a macroscopic structure leaving spaces of a defined depth at the interface. In one embodiment, the structure visible to the naked eye can be constructed by a pattern of protrusions (spacers) that produce an adhesive gap of a defined thickness, wherein the vibrations enable improved distribution and wetting. In addition to making, it ensures reliable filling of the gap.

Also, these structures tend to increase the surface thereby improving adhesion. These structures may further strengthen the bond, for example, by constructing a embossed fit structure.

In a particular group of embodiments, the second object on the side facing the first object may include a geometrically structured thermoplastic contact. When mechanical vibrations act, these geometries can function as energy directors and the liquefaction process of the thermoplastic can be started locally. Thereby, an interpenetrating network is formed between the thermoplastic and the resin, which on the one hand can improve the attachment strength and on the other hand compensate for geometrical non-uniformities ( compensation of geometrical irregularities) can be made possible. Further additional heat is generated by absorption of vibrational energy by the thermoplastic which further accelerates the curing process. Finally, the interpenetrating network forms an impact resistant interlayer, in particular due to the ductility of the thermoplastic material, which makes it possible to compensate for the fragility of the adhesive bond through the resin.

This concept may alternatively or additionally be applied to a first object comprising a thermoplastic material on the first attachment surface.

In addition to or as an alternative to the indentation(s) of the second attachment surface, a structure comprising at least one indentation (channel, groove, hole) may be provided on the first attachment surface. This indentation of the first object can be prefabricated (e.g. in a Resin Transfer Molding process in which the fiber composite part is manufactured and/or in a removal step, e.g. affecting the base material) as well as by a material removal step by means of affecting the fibers (sandblasting, etching or the like).

The first object - or the second object if mechanical vibrations act on the first object - can be placed on a support, in particular a non-vibrating support, during the pressing step. Applying vibration from both sides, ie pressing the vibration tools against both the second object and the first object, is also optional.

As used herein, the term “fiber composite part” generally refers to parts comprising a structure of fibers, such as an arrangement of fiber bundles, a textile structure of fibers or any other structure of fibers, and a base material in which the fibers are embedded. is referred to as Often, in such structures, the fibers are so-called “continuous fibers”, ie fibers having lengths that may exceed 10 mm. The fibers may be, for example, carbon fibers. These fiber composites are often referred to as “carbon fiber composites” or “carbon-fiber-reinforced polymers” or “carbon-fiber-reinforced plastics”. referred to as "; Often also referred to simply as “carbon”. Fibers other than carbon fibers such as glass, ceramic or polymer fibers are not excluded.

In a group of embodiments, the second object is a fastener having an anchoring plate (or "fastener head") and a fastening element joined to the anchoring plate. The fastening element may have any characteristics of prior art fasteners, for example threaded bolts (inner thread and/or outer thread), unthreaded, for example glue channels ( It can be bolts with glue channels, pins, nuts, hooks, eyelets, bases for bayonet couplings, etc. A fastener may consist essentially of fasteners marketed under the trade designation “bighead” in embodiments of this group and is intended to be pasted to the surface of another object.

The anchoring plate of this group of fasteners may have at least one through opening in addition to or as an alternative to the previously discussed optional structures of the second attachment surface. During the process, portions of the resin will be caused to penetrate into the through opening(s) and thereby contribute to the fastening effect.

In this group of embodiments, the anchoring plate is provided with at least one spacer projecting from the second attachment surface. These spacers define a minimum distance between the first and second attachment surfaces, thereby controlling the thickness of the resin layer. On the one hand, the spacer size and the resin composition and the requirements of adhesion (eg compensation for thermal expansion mismatch) can here be adjusted relative to each other.

The spacer(s) may in particular be disposed close to the opening(s), for example forming a collar surrounding the opening(s). In this embodiment, the spacer(s) has the additional effect of helping to control the amount of resin flowing backwards towards the proximal portion by the effects of urging force and vibration.

The vibrating tool used to couple the vibrations into the assembly may be adjusted relative to a second object (fastener) to engage the vibrating tool such that it is pressed directly against the proximally facing surface of the anchoring plate. In many embodiments, particularly including but not limited to those in which the vibration is longitudinal vibration, the vibration tool is thus adapted to be pressed against the proximal facing surface of the anchoring plate.

To this end, the vibrating tool may comprise a receiving indentation for the fastening element and may make force and vibration transmission contact with the anchoring plate.

The receiving indentation or other structure of the vibrating tool may be installed to be a guiding structure cooperating with a stationary element for guiding the second object relative to the vibrating tool. This guide structure may be configured as a holding structure that cooperates with the holding element to secure the second object to the vibrating tool. Alternatively, it may for example be a loose guide structure which laterally guides the fastening element during decoupling (disengagement) with respect to axial relative movements.

A possible issue may be the confinement of the resin, which may initially be relatively flowable, during processing, especially since mechanical vibrations initially improve the mobility of the resin.

A first option of lateral confinement is to apply a peripheral confinement (confinement) feature to the second object and/or to confine the resin during the step of pressing the second object and the first object against each other and causing mechanical vibration to act. Or to provide to the first object. Such peripheral constraining features include, for example, a peripheral annular distally facing collar of the second object of the same or similar extension as the spacer(s) (if present). can do. This peripheral annular collar may alternatively function (only) as a spacer. providing the second object and/or the first object with a surface shape that protrudes (ridges) away from the resin side at the location of the resin, ie the second object projects toward the proximal portion and/or the first object projects toward the distal portion It is also possible to protrude. Thereby, pockets are formed for the resin. Containment by such a shape may be such that the pocket is laterally closed, or the pocket is opened, thereby allowing any reduced lateral flow of resin out of and/or into the pocket.

A second option of lateral restraint is to provide the vibrating tool with peripheral restraint features. This peripheral constraining feature may include an annular projection protruding toward the first attachment surface and at the periphery of the second object.

According to a third option, a separate restraining element may be used which at least partially surrounds the second object (eg an anchoring plate if applicable) to restrain the resin.

Options may be arbitrarily combined.

Dispensing the resin prior to bringing the attachment surfaces together may include using a dispensing tool to dispense the resin to the first attachment surface and/or the second attachment surface.

In a group of embodiments, the method comprises applying a resin to a relatively large portion of one surface of the objects prior to positioning the second object relative to the first object and crosslinking the resin by mechanical vibration. (cross-link) and activating (activating).

This group is particularly suitable for embodiments in which the second object (and for example also the first object) is planar and sheet-like or has at least a planar, sheet-like part.

When two objects having a relatively large common surface are joined to each other by adhesive bonding, with an adhesive between the attachment surfaces, in a manufacturing process after bringing the first and second objects together according to the prior art, the process is We had to wait for the adhesive to cure sufficiently. Alternatively, rivets have been used to temporarily stabilize the relative positions of the first and second objects until the adhesive has fully cured. Rivet connections have well-known advantages that are briefly discussed at the beginning of this specification.

According to the mentioned group of embodiments, activation is performed selectively, only for a discrete location or for a plurality of discrete locations, and the resin is affected at locations other than the discrete location(s). is maintained without receiving

Thereby, the resin provisionally (temporarily) stabilizes the assembly of the first object and the second object at discrete location(s), eg, after a waiting time or heating step, until the adhesive material is fully cured. ) can be done. Thereby, the embodiments of this group have the advantage of provisional stabilization (with the possibility of further machining of the assembly) without the disadvantages of a rivet or similar (screwing, etc.) connection.

In this group of embodiments, a possible challenge here is to vibrate without dissipating too much vibrational energy laterally through the second object, for example along the second object sheet plane, while depending on the stiffness of the second object. It can be that it can be difficult to selectively couple to the desired spot via the second object.

In a subgroup of embodiments, the second object has a material that is locally sufficiently flexible to selectively couple the vibrations to a portion of the resin directly underneath the vibration tool that couples the vibrations into the second object.

Additionally or alternatively, the second object comprises a local deformation, for example an embossment having energy directing properties. For example, such a localized deformation may include a corrugated structure, whereby the corrugation functions as an energy director.

Additionally or alternatively, the second object may comprise a vibration decoupling structure (acting in a joint-like manner) around the discrete location, for example a groove.

As a further alternative, which can be selectively combined with the mentioned possibilities, an auxiliary element is arranged at a discrete position between the first object and the second object. This auxiliary element functions as an absorber for mechanical vibration energy and thereby heats the surrounding resin material in a targeted manner. The auxiliary element may comprise an energy director for this purpose. This auxiliary element may comprise a thermoplastic material.

In embodiments, such an auxiliary element may comprise a thermoplastic elastomer. At this point, the E-modulus can be adjusted (after cross-linking) to a matching modulus of the resin. The mechanical properties will then be at best minimally affected.

In embodiments, this auxiliary element may be deposited with a resin. For example, if the resin is deposited as a resin bead by a matching automated tool, the auxiliary element may be deposited by the tool along with the bead.

In embodiments, the auxiliary element may be a flexible planar structure such as a mesh or other similar that forms energy directing structures distributed over a large surface, for example in a regular pattern, for example, It may be formed to extend over a large portion of the interface between the first object and the second object. A flexible planar structure in this regard is a planar structure that can be deformed without significant force input and without significant springback effect, such as pieces of textiles, meshes, foils, etc. In some embodiments, instead of a flexible planar structure, the auxiliary element may also be a stiff planar structure.

In embodiments with an extended auxiliary element, the deposition of the auxiliary element does not necessarily have to be with precise positioning, even if the position of the adhesive connection with vibration-triggered rapid curing needs to be precisely defined. Because this precise definition can be caused by the position of the tool to which the vibration is applied.

Depending on the possibility, the position of the auxiliary element will be defined by a guiding indentation (guide hole) of the first/second object cooperating with a corresponding structure of the first or second object, for example a corresponding protrusion of the auxiliary element. can

If the auxiliary element comprises a thermoplastic material made flowable during the process, its flowing part can lead to material flow in addition to the heating effect, whereby an additional structure having a stirring function in the resin and contributing to the fixing effect of the resin induce

In addition to functioning as an absorber, the auxiliary element may also function as a spacer, thereby defining the thickness of the resin between the first object and the second object.

In a group of embodiments, the first object or the second object at least partially has a thermoplastic material and the other (the second object or the first object) during the step of applying a pressing force and mechanical vibration, the first object or each having a piercing portion provided for piercing each into the thermoplastic material of the second object.

The perforation may comprise a perforation tip and may optionally comprise an undercut with respect to the axial direction.

The perforations act as vibrational energy directors during processing and make the thermoplastic material flowable locally by the impact of the vibrational energy. This first has the effect of enabling the penetration of the perforations into the first object whereby further anchoring is achieved (in addition to the effect of the resin) after resolidification of the flowable thermoplastic parts. Also, possible disruptions (breaks) in the first object material are leveled (flattened) by the flowable thermoplastic (healing effect). As a second effect, the absorbed mechanical vibrational energy leads to localized heating of the assembly around the interface between the perforation and the first object, whereby the resin is subjected to additional local activation, as previously described.

The perforations provide rapid and significant stability even when the entire resin does not cure for the reasons mentioned. This can be important in manufacturing steps where the assembly needs to have sufficient stability quickly to move on to the next manufacturing step.

In another group of embodiments, the second object and/or the first object is made at least in part from a thermoplastic material and is brought into contact with the first object or the second object during processing - a tip or an edge, respectively. at least one energy directing feature - such as a protrusion forming an edge. When vibration and urging force are coupled into the assembly, energy will be absorbed locally at the location(s) of the energy directing feature(s). This will cause the thermoplastic material of the energy directing feature to become locally flowable and cause deformation. Due to the absorption of energy at the protrusions, the resin adds additional properties around the protrusions leading to local hardened zones that ensure primary stability spots even when the entire resin has not yet cured. You will receive additional local activation.

In these embodiments, the flowable material around the energy directing features is, for example, by causing a weld to each other object to form a embossed fit bond, etc. (if materials are selected correspondingly) and/or or the ability to contribute to process and/or stationary effects, for example by contributing to process control, such as by defining a distance between a first object and a second object at which the mechanical resistance to further movement with respect to each other becomes high. Optionally, it may be additionally provided.

In embodiments, the second object and/or the first object are formed such that the resin further causes a embossed fit bond to the adhesive bond. To this end, the second object and/or the first object may be provided with a structure into which the resin flows in such a way that an undercut is made after re-solidification. In a subgroup of these embodiments, where the second object/first object has a relatively thin sheet-like portion, this structure may include an opening in this second object/first object through which a portion of the resin may escape. and can flow beyond the opening into the open space, ie to a proximal portion of the second object portion having an opening and/or to a distal portion of a first object portion having an opening, respectively. Thereby, a button-type embossed fit bond is generated after curing of the resin.

The tool for applying the vibration may be a sonotrode coupled to a device for generating the vibration. Such a device may be, for example, a portable electric device comprising suitable means, such as a piezoelectric transducer, for generating vibrations.

Mechanical vibration may be longitudinal vibration; A tool applying vibration may vibrate essentially perpendicular to the surface portion (and the tool is also pressed longitudinally); This does not exclude lateral forces in the tool, for example for moving the tool over the surface portion.

In other embodiments, the oscillation is transverse oscillation, ie the oscillation is mostly oblique, eg perpendicular to, about the proximodistal axis (proximodistal axis) and thus eg the first and parallel to the second attachment surfaces. In this case, the vibration energy and amplitude may be similar to the parameters of the longitudinal vibration.

In a further group of embodiments, as can be seen as a sub-group of embodiments with transverse vibration, the oscillation may be a rotational oscillation, ie the vibrating item vibrates in a back-and-forth torsional motion.

In many embodiments the vibrating tool is used to press the second object against the first object while the vibration is acting. To apply a counter force to the first object, a non-vibrating support may be used (ie the vibrating tool presses the second object and the first object against the non-vibrating support). Such a non-vibrating support may be, for example, a workbench or may be constituted by a frame for holding a first object or the like.

In a group of embodiments, a control foil is used for the process. Such control foils (or auxiliary foils) may be disposed between a non-vibrating support and a first object and/or between a tool and a second object (or generally between a tool and the object(s) against which it is pressed and/or between a non-vibrating support and/or with a non-vibrating support). between the object(s) pressed against it).

Such a control foil may, for example, have a plastic such as polytetrafluoroethylene (PTFE), or paper, which does not flow under the conditions applied during processing.

The foil has the following possible functions:

- force impact distribution: in particular when the first and/or second object is sheet-like, these are the frequency and wavelength of the coupled-in vibration and, respectively, generally unequal resonant frequencies. and their own vibrational behavior with wavelengths. This will guide the coupling at only certain contact points instead of over the entire contact surface and will lead to losses. A relatively soft foil will counteract (balance) these discrepancies (will cancel out impedance mismatches) and thereby improve the coupling properties.

- Heat flow prevention: Often, the applicable sonotrode and/or the applicable non-vibrating supports (eg workbenches) are made of metal or other good conductor of heat. Close direct contact between the sonotrode/support on one side and the second/first object on the other side will result in significant heat flow to the sonotrode/support. The efficiency of the process is lowered as a result. The control foil has an insulating effect that drastically reduces the heat flow.

Here the control foil is used as an auxiliary element which is removed after processing. To this end, the control foil is made of a material that does not stick to the second/first object.

Optionally, the control foil may be present as a coating of the vibrating tool/non-vibrating support.

Mechanical vibrations may be ultrasonic vibrations, for example vibrations of frequencies between 15 kHz and 200 kHz, in particular between 20 kHz and 60 kHz. For typical sizes of second objects (for example with characteristic lateral dimensions of about 1 cm) and for dimensions of composite parts for example for the automotive industry (body parts), although the power to be applied depends on the application It can vary greatly, but a power of about 100-200 W turned out to be sufficient.

In certain embodiments, there is the option of performing the method by a tool comprising automatic control of the pressing force. For example, the device may be configured to switch on vibration only when a certain minimum pressing force is applied, and/or to switch off vibration as soon as a certain maximum pressing force is achieved. The latter in particular can be beneficial for parts thereof, such as certain body parts, for which undesired deformation is to be avoided.

To this end, according to a first option the ability of a piezoelectric transducer to measure the applied pressure can be used. According to a second option, a special mechanism may be present in the device. For example, a unit containing a transducer and to which a tool (sonotrode) is attached may be slidably mounted against a spring force within a casing. The device may be configured to be able to be switched on only when the unit is moved by a certain minimum displacement and/or not by more than a certain maximum displacement. To achieve this, means well known in the art may be used, such as shading films, sliding electrical contacts, position detection switches or other means. Also, a collapsible sleeve or the like of the kind described below may contain or actuate a contact or switch or the like to control the pressing force.

The vibration frequency can affect the way vibrations work. Lower frequencies will lead to longer wavelengths. By adapting the wavelength to the dimensions of the part to be finished, the operator can determine at what depth the effect of vibration is strongest and the energy is predominantly in the 'near field' regime, in the 'far' region. It can affect whether it is absorbed in the field' regime or in the intermediate regime.

The present invention also includes a kit of parts for carrying out the method, the kit of parts comprising a resin material (more precisely: a raw material for a resin material, which is for example two components) and a second object and a vibration application having a distal outcoupling face adapted to a proximally facing incoupling face of the second object. tools) (e.g. sonotrode). The kit may further include a material removal device, such as a sandblasting device.

The present invention overcomes the drawbacks of the prior art methods and provides a method of fastening a further second object (eg a connector) to a first object which forms a particularly strong reliable mechanical bond.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, methods for practicing the present invention and embodiments are described with reference to the drawings. The drawings are schematic. In the drawings, the same reference numerals denote the same or similar members. The drawings show:
1a to 1d show cross-sectional views of a fiber composite part during different stages of a method of attaching a second object thereto;
2 shows a fiber composite part with prepared exposed spots;
3 shows an alternative construction of a fiber composite part with a second object and a sonotrode;
- Figures 4 to 6 show different second objects in a bottom view and in cross section;
7 shows a configuration with a second object comprising a plurality of components;
8 shows a fastener constituting a second object;
FIG. 9 shows a partial cross-sectional view through an anchoring plate of a fastener of the kind shown in FIG. 8 ;
- Figures 10 to 14 show partial cross-sectional views of further configurations;
15 shows a sonotrode;
16 shows an assembly of a first object and a second object;
17 and 18 show cross-sectional views through an assembly of a first object, a second object and a sonotrode, wherein a resin bead is dispensed between the first object and the second object;
19 shows an embodiment of a second object;
20 shows a cross-sectional view through an arrangement with auxiliary elements;
21 to 23 show top views of embodiments of auxiliary elements;
- Figure 24 shows an auxiliary element with a guide nipple;
25 shows a bottom view of a further second object;
26 shows a partial bottom view of an even further second object;
- Figure 27 shows cross-sectional views through an assembly of a first object, a second object and a sonotrode, wherein a resin bead is dispensed between the first object and the second object;
- Fig. 28 shows a modified example of the arrangement structure of the first object and the second object;
- Figure 29 shows a further cross-sectional view through the assembly of a first object, a second object and a sonotrode, wherein the resin beads are dispensed between the first object and the second object and with an auxiliary element;
- Figure 30 shows a partial plan view of the auxiliary element;
- Figure 31 again shows in cross section the arrangement during processing, the arrangement further comprising control foils;
- Figure 32 shows a still further sectional view through the assembly of the first object, the second object and the sonotrode, wherein the resin is dispensed between the first object and the second object;
- Fig. 33 shows a cross-sectional view of an arrangement with a double-fitting fit;
- FIG. 34 shows a partial plan view of a second object with respect to the arrangement of FIG. 33;
35 and 36 show still further cross-sectional views through the assembly of the first object, the second object and the sonotrode, wherein the resin is dispensed between the first object and the second object;
- Figure 37 shows the resulting assembly after the process shown in Figure 36;
- Figure 38 shows a variant of the assembly of Figure 36 without a sonotrode; and
39 shows a partial bottom view of a second object.

1a shows in cross section a fiber composite part 1 with a structure of fibers 11 embedded in a matrix 12 of cured resin. For illustration purposes, in all illustrated embodiments, the fiber composite part is assumed to have a general flattish shape, such as, for example, a body part, an aircraft wall, and the like. However, all embodiments of the present invention are also applicable to first objects that are not slightly flat and have any other shape.

1A schematically illustrates the step of removing matrix material from a spot on an attachment surface (the proximal facing surface; the top surface in the orientation shown in FIG. 1A ). A sandblasting device 40 removes the base material but its energy forms a jet 42 of abrasive particles that is not sufficient to systematically damage the fibers 11 .

In the configuration of FIG. 1A , a mask 41 is used to cover portions of the surface that are not sandblasted. Instead of using a mask, a sandblasting machine can aim to remove the substrate only at the required location.

1b shows the fiber composite part 1 after the step of exposing a portion of the structure of fibers: along the exposed surface portion 13 of the exposed fibers 11 the substrate is essentially removed to at least some depth. . In practice, the depth may be several tens of micrometers or more, for example 50 micrometers or more.

Thereafter, the resin portion 3 is placed on the exposed surface portion 13 (FIG. 1C). The resin may be, for example, a two-component mix of resins, for example an epoxy or polyester resin. The resin portion may optionally completely cover the exposed surface portion 13, but this is not essential.

In addition to or as an alternative to dispensing the resin part to the fiber composite part 1 , the resin may also be dispensed to the second object.

Thereafter, as shown in FIG. 1D , the fiber composite part and the second object 2 are each (consisting of a distal-facing surface of the second object 2 and a proximal-facing surface of the fiber composite part), respectively. The adhesive surfaces of the resin between the surfaces are pressed against each other.

In the configuration shown, the second object comprises a number of indentations, ie channels 21 in the second attachment surface. Due to the pressing force, the resin will at least partially fill these channels 21 .

Also (this is an option independent of whether the second object contains indentations), the second object 2 is made of a fiber reinforced composite, and the fibers 24 are exposed at locations where they will come into contact with the resin. do.

In the step of pressing, the sonotrode 6 presses the second object 2 against the fiber composite part 1 , the latter being placed (supported) against a non-vibrating support (not shown in FIG. 1d ). At the same time, mechanical vibrations, in particular ultrasonic vibrations, are coupled into the second object. By the effect of vibration, the resin is caused to effectively penetrate the exposed fibers of the fiber composite part and, where applicable, of the second object. At the same time, the absorbed mechanical vibration energy will cause the resin to be locally heated at the interface between the fiber composite part and the second object. Thereby, the curing process in these places is significantly accelerated, whereby the period between the batch and sufficient curing for the connection to be mechanically stable is significantly reduced, for example from a few minutes (without vibration) to a few seconds ( with vibration) is reduced.

This does not affect the potential excess portions of the resin laterally outside of the attachment location, so these excess portions can be easily removed after processing.

The sonotrode 6 comprises an optional guiding projection 65 which cooperates with the guiding indentation 26 of the second object. These cooperating guiding features are optional for all embodiments.

FIG. 2 shows a fiber composite part with distinct layers 12 in a step corresponding to the step shown in FIG. 1b . The process according to the invention can be carried out so that the depth of exposure of the fibers 11 at the attachment site is less than or equal to the thickness of the proximal-most layer, or, as shown, several layers 12 . of the fibers may be exposed.

Fig. 3 shows a configuration similar to that of Fig. 1d. The following additional features are shown, which are independent of each other and may be implemented individually or in any combinations.

- the second object 2 is heterogeneous and comprises a part 25 of a plastic material (eg fiber-reinforced composite) and further comprises a part 26 of a different material, eg metallic. (As a further alternative not shown in FIG. 3 , the second object may be homogeneous or heterogeneous, for example metallic (of aluminum, steel, pressure die-cast magnesium), or a thermoplastic material, e.g. for example, injection molded, or made of ceramic or any other suitable material, or a combination thereof.

- the second object 2 , which is a connector, comprises a fixing structure for fixing a further object to the second object (and thereby to the fiber composite part 1 ). Specifically, in the embodiment shown, the fastening structure is constituted by an internal thread of a nut part, said nut part constituting a part 26 made of a different material in the embodiment shown. More generally, the anchoring structure may be formed by any one or combination of parts in a dissimilar body. The anchoring structure may also be present in a homogeneous second object.

- the second object 2 has a (central) part of increased thickness and a (peripheral in FIG. 3 ) part of a smaller thickness. This can be advantageous if some depth is required - for example for fixed structures - but the overall dimensions should be minimal. Due to the smaller thickness of the portion, the footprint of the attachment location may be larger for a given second object volume.

The shape of the sonotrode 6 is adapted to the shape of the second object 2 . In particular, in the configuration shown the sonotrode comprises a central indentation and a peripheral outcoupling surface, whereby only the outcoupling surface is in contact with the second object during processing.

- the channels 21 are radial channels so that the mass flow of the resin material can be controlled even if the amount of material dispensed is not precisely selected.

4 shows an embodiment of a second object (connector) with radially running channels 21 . An additional, proximodistal channel 28 is not limited to the second attachment surface but runs proximally from the attachment surface and constitutes a through longitudinal bore. It can be used for equating the resin flow or even for dispensing the resin after positioning the second object.

The channel(s) of the myal channel 28 and the distal surface of the second object (connector) are independent of each other, i.e. the source channel 28 is not required for any second object having channels in the distal surface, and vice versa. The same is also true.

In the variant shown in FIG. 5 , the channels 21 are not radial but circumferential.

In the variant of FIG. 25 , the circumferential channels 21 are connected by means of radial connections 121 , whereby shear flows are possible and resin for cavitation effects. is reduced compared to the configuration with unconnected circumferential channels as shown in FIG. 5 .

6 , the indentations are formed by blind holes 29 disposed in the pattern.

As an even further alternative, radial and circumferential channels can be combined, resulting in a pattern of protrusions (nubs-like and/or feet-like structures. More generally, The arrangement of these projections of any shape - eg acting as spacers of equal thickness - can define, by their height, a minimum overall thickness of the resin layer, said minimum thickness being 0.05 mm. and 1 mm, for example between 0.1 mm and 0.5 mm.

In general, independent of the shapes of the first/second object, and independent of whether the first object comprises a fiber composite, in addition to or as an alternative to the structure(s) discussed, the following approach may be chosen: can:

- the second object and/or the first object comprises a thermoplastic material along their respective attachment surfaces.

- The resin is applied as a component of the preparation which in addition to the resin also contains thermoplastic particles, in particular a thermoplastic powder which is mixed into the resin. Thereby, the particle size will initially define the thickness of the bonding gap. Also, mechanical vibrations will cause the thermoplastic particles to become flowable and weld to the respective thermoplastic material along the attachment surface in addition to speeding up the curing process. Again (as in the approach previously discussed), a network of interpenetrating structures is formed, resulting in an impact resistant, strongly bonding interlayer.

7 illustrates the principle of attaching a second object simultaneously or sequentially at multiple attachment locations. For example, the second object may have a plurality of attachment parts, their spatial relationship to each other being precisely defined. In prior art approaches (except gluing), this required drilling holes into the fiber composite part with high precision at locations corresponding to attachment locations. With the approach according to the invention, it is sufficient to provide only approximately exposed surface portions 13 where adhesion takes place. The attachment locations are attached simultaneously (or in turn - or in subgroups - in the manner previously discussed).

In the embodiment of FIG. 7 , the second object 2 comprises a plurality of second object anchoring parts 2.1 , 2.2 , 2.3 fixing the main part 2.10 to the fiber composite part 1 . In the embodiment shown, the anchor parts are reversibly attached to the main part 2.10, for example by means of a clip connection. In order to secure the main part 2.10, instead of having to precisely place the anchor parts (which may be the case for conventional dowels) in order to conform to the pattern of connection positions of the main body, a second object (2) can be arranged relative to the composite part (1) with attached anchor parts. A fastening process can then be carried out, after which the main part 2.10 is reversibly removed if required, for example if it is desired that the main part is not exposed to subsequent manufacturing steps. can be

8 shows a second object 2 as a fastener having an anchoring plate 31 (or "fastener head") and a fastening element 32 joined thereto. show 9 shows a partial cross-sectional view through the anchoring plate 31 of FIG. 8 . The fastening element may have any of the characteristics of prior art fasteners, for example threaded bolts (as shown), unthreaded bolts, pins, nuts, hooks, eyelets, bayonet couplings. ) may be a base for The fastener may in this case consist essentially of fasteners sold under the trade name “bighead”.

Embodiments of the method according to the invention are particularly suitable for bonding fasteners of this kind to any object by means of an adhesive resin, including but not limited to an object comprising a structure of fibers embedded in a polymer matrix. can

In a first group of embodiments, the fastener is configured like prior art fasteners, for example having an essentially planar anchoring plate 31 with a plurality of through openings 33 .

In a further group of embodiments, the fastener has a structure suitable for processing. In particular, the anchoring plate 31 can be provided with distal spacer elements 35 projecting from the distal plane of the anchoring plate on the distal side. These spacer elements 35 may define a minimum distance between the surface of the first object and the distal surface of the anchoring plate, whereby a resin layer of some minimum thickness is maintained between the first object and the second object after processing. guarantee to be

Additionally or alternatively to the spacer elements, the distal facing surface of the anchoring plate 31 may comprise structures such as those described with reference to FIGS. 3 to 6 or FIG. 1D .

In embodiments, a structure that ensures that a resin part of a certain minimum thickness is sustained during application of mechanical vibration may be of special importance in view of the approach according to the present invention. This is because, compared with the conventional uses of the resin as an adhesive, the fluidity of the adhesive resin can be sharply increased by mechanical vibration.

In the configuration shown, the spacer elements 35 are collar-like projections surrounding the openings 33 . However, comprising a pattern of discrete spacers distributed across the distal surface of the anchoring plate, or extending along the periphery of the anchoring plate and projecting therefrom towards the distal portion, thereby also comprising a single peripheral collar that also defines the resin Other arrangements of spacer elements 35 may be possible.

26 shows the option of separate (individual) spacer elements 35 surrounding the openings 33 instead of a continuous collar.

In embodiments where the second object is a fastener having an anchoring plate and an anchoring element, and the anchoring element has a portion proximally protruding from the anchoring plate, the tool used to couple mechanical vibration into the second object may be specially adapted have.

10 schematically shows the first possibility. The sonotrode has a receiving indentation 61 having a mouth on its distal outcoupling face, in which a fastening element ( 32) is accepted. Thereby the tool (sonotrode) and the second object are adapted to each other so that the tool is pressed directly against the proximal facing surface of the anchoring plate.

The tool may be provided with a guiding structure, such as inwardly directed guiding projections 62 to guide a second object relative to the tool. Such a guide structure can in particular engage a fastening element, which is the case for the schematically illustrated guide projections 62 of the embodiment shown in FIG. 10 .

In embodiments, the guiding structure may be configured as a securing structure cooperating with the securing element to temporarily secure the second object to the sonotrode. This possibility is schematically illustrated in FIG. 11 . 11 , the second object/fastener has a nut 36 fixed to the anchoring plate, for example welded, which nut functions as a fastening structure. The tool 6 includes a threaded projection 65 adapted to the internal thread of the nut 36 , whereby the fastener can be threaded onto the tool for processing.

Similar configurations are also possible for other fastening elements, for example indentation with an internal thread for cooperating with the threaded bar of the fastener.

12 illustrates a possible issue of limiting the resin to a location on the attachment surface where a first object is in contact with a second object (attachment location).

The first possibility has been mentioned above, ie providing the second object with a confining feature, for example a peripheral collar.

Fig. 27 shows a modification of this concept. The first object 1 and/or the second object 2 has an indentation 131 facing towards the resin 3 (which here becomes an outward bulge), whereby the pocket 132 is It is formed for this resin. These pockets can be closed laterally or they can be opened laterally, as shown in FIG. 27 , whereby any lateral flow of resin 3 is kept possible.

In the embodiment shown in FIG. 27 , both the first object and the second object are shown as sheet metal, with each indentation 131 formed as a bulge away from the resin side, ie towards the distal for the first object. , and is formed toward the proximal portion for the second object. Of course, there are other methods for forming this pocket of the type shown by, for example, die casting, molding, etc., depending on the properties of the first object/second object.

Figure 28 shows that when both the first and second objects 1, 2 each have indentations 131 for forming pockets, the indentations are optionally laterally offset/shifted relative to each other. shifted, thereby schematically showing the principle by which cavitation effects can be reduced.

A second possibility is shown in FIG. 12 . The tool 6 has a peripheral collar 66 protruding towards the distal portion, thereby confining the resin 3 . The dimensions of this collar are selected such that the collar 66 does not make direct physical contact with the first object surface during processing, under applicable conditions, for example, taking into account spacer elements of the type described above, if present.

A third possibility is a separate confining element 53 , for example as shown in FIG. 13 . This separate limiting element may for example be a short tube element which surrounds the tool 6 but is vibrationally de-coupled from the tool 6 . This separate restricting element may be arranged to surround the attachment site before or after dispensing the resin 3 and may for example abut against the proximal facing surface of the first object 1 .

The above three possibilities may be applied independently of each other or may be combined, and may also be combined in any sub-combination.

In embodiments, the second object has a through hole, such as for example through holes 33 of the anchoring plate 31 . In these embodiments, the resin material may flow through the through holes towards the proximal portion. This may have the effect of contributing to the attachment properties by causing a positive-fit effect, wherein the second object is partially embedded in the resin material after curing of the resin material.

In embodiments where the second object has a through hole, measures are taken to prevent the resin material from sticking to the surface of the tool after processing.

The first such measure is to ensure that the distal-facing outcoupling surface of the tool has properties that prevent such sticking, for example by having a corresponding anti-adhesive coating.

A second optional measure is shown very schematically in FIG. 13 . The tool may have an indentation 67 at a location corresponding to the location of the through hole. This option is independent of the other features shown in FIG. 13 ; In particular, it is applicable independently of the limiting element 53 .

14 shows an embodiment of a configuration in which the vibration is transverse vibration and not longitudinal vibration, in contrast to the above embodiments. The sonotrode 6 of FIG. 14 is installed for transverse oscillation. It includes a receiving opening 61 configured to receive a stationary structure 32 . In particular, in FIG. 14 a receiving opening having an internal thread applied to a thread of a fastening structure, which is a threaded bar, is shown, the fastener being, for example, as shown in FIG. 8 . The sonotrode 6 has a ring-shaped skirt 68 that is pressed against the peripheral portion of the anchoring plate 31 during processing and thereby couples the pressing force and, together with the receiving opening, mechanical vibrations to the anchoring plate 31 . . For reasons of symmetry, the sonotrode 6 shown in FIG. 14 has a proximal ring-shaped skirt 68 in addition to the distal ring-shaped skirt 68 pressed against the anchoring plate. For this reason, it may be possible to perform the process in parallel on the two assemblies, wherein the sonotrode is between two first objects which are pressed against respective second objects introduced from opposite sides. is clamped on Two further coupling positions may be present on opposite sides of the sonotrode parallel to the drawing plane of FIG. 14 .

Another sonotrode 6 suitable for example for transverse oscillation, for example in a 'wedge-reed' type configuration, is shown in FIG. 15 . The sonotrode includes a receiving opening 61 for receiving a fixed structure (eg a threaded bar). Similar to the embodiment of FIGS. 11 and 14 , the receiving opening can optionally be provided for coupling to a stationary structure. The sonotrode is subjected to vibrations coupled into the sonotrode by way of a coupler acting from the side and causing a bending oscillation of the sonotrode, for example as schematically shown in FIG. 15 . installed and mounted for lateral oscillation of the distal end portion by the

The sonotrode of the embodiment shown comprises a plurality of wings 69 for coupling vibrations into lateral portions of the anchoring plate instead of a ring-shaped skirt. Adaptation to a sonotrode with an outcoupling skirt or other coupling face as in FIG. 14 may be readily possible.

The concept of transverse vibration discussed with reference to FIGS. 14 and 15 is described herein using suitable coupling means between a vibrating tool (sonotrode) and a corresponding second object, in addition to the fasteners only shown in FIG. 14 . It is important to note that it can also be transferred to other second objects/connectors and other fastening concepts.

16 shows very schematically a possible application of embodiments of the invention. The first object 1 and the second object may be joined to each other by adhesive bonding, and the first object and the second object are both relatively large. In the manufacturing process, curing of the adhesive between objects until the bond is strong enough for further manufacturing steps can cause significant delays. Accordingly, an approach according to embodiments of the present invention is to use the fixation method described herein on a number of discrete (discrete) spots 81 to activate the resin in these spots. Thereby, the bonding is caused to be sufficiently stable in a rapid process. The resin portions between the discrete spots 81 can thereby slowly harden while the assembly of the first object and the second object is in further processing steps.

Fig. 17 shows the arrangement of the first object 1, the second object 2, and the resin part 3 therebetween. 17 , the second object, and also the first object, is a relatively thin sheet-like object, for example, a thin metal plate. It is assumed that both the first object and the second object have a relatively large in-plane (x-y) extension, and the resin part can be applied to at least one of the objects, for example by means of a corresponding robot or an extended adhesive bead. It is applied extensively on the surface. As shown for FIG. 16 , the surface of the resin is too large for mechanical vibration to be applied extensively over the entire area covered by the adhesive, and curing can only occur in discrete spots. The remaining portions of the adhesive may then cure at a much slower rate and/or may be induced by heating.

A possible challenge in this case depends on the stiffness of the membrane (lamellar metal) while it can be difficult to selectively couple the vibrations through the second object to the desired spot without too much vibrational energy being dissipated by flowing laterally.

- in embodiments, the second object is made of a locally sufficiently flexible material (e.g. a membranous thin sheet) to selectively couple the vibrations to the portion of the resin just below the sonotrode that couples the vibrations into the second object. material) has.

- In other embodiments, the second object comprises a local deformation, for example an embossment with energy directing properties.

In FIG. 17 , the relief forms a local indentation/bead 91 . As shown in FIG. 18 , which shows the configuration of FIG. 17 in cross-section along a plane perpendicular to the plane of cross-section of FIG. 17 , the indentation corrugates at the bottom. Thereby, a number of effects can be achieved:

- The indentation as a whole and in particular the corrugation provides prominent structures such as edges with energy-directing properties. Absorption of vibrational energy occurs in these structures in an enhanced manner. As a result, the curing process is set around these structures as indicated by regions 95 in FIG. 18 .

- said structure influences the vibrational behavior and can separate the areas of the indentation 91 slightly from the areas around the indentation 91 .

- the indentation with the above structure functions as an interior distance holder when the first and second objects are pressed against each other and the resin remains fluid, thereby defining the thickness of the adhesive part after processing .

19, which shows the second object 2 in cross-sectional view (top panel) and in plan view (bottom panel), shows a variant of the structure with indentation (which can optionally be provided with additional structures similar to FIG. 18 ) In this variant the indented region is mainly surrounded by an embossed groove 97 which functions as a joint-like structure to enable vibrations of the part surrounded by the groove.

The embodiments of FIGS. 27-28 discussed above - similar to the embodiments of FIGS. 17-19 , but the adhesive does not move sideways and stays in place due to the outward bulges of the second object and/or the first object Further examples of embodiments comprising selectively coupling vibrations through a second object to a desired spot without being dissipated by too much vibrational energy flowing laterally.

A further possible solution to the problem of selectively coupling vibrational energy into the desired spot is shown in FIG. 20 . An auxiliary element 101 is arranged between the first object 1 and the second object 2 . The auxiliary element functions as a distance holder and thereby defines the thickness of the resin part 3 . These include thermoplastics that can be liquefied by mechanical vibrational energy. The thermoplastic material of the auxiliary element when mechanical vibration energy is applied to the second object locally at the position of the auxiliary element 101 , for example while the second object 2 and the first object 1 are pressed against each other. In particular, it absorbs vibrational energy due to external and/or internal friction, thereby being locally heated. As a result, heat is also transferred to the surrounding resin material 3 .

In embodiments such as FIG. 20 , the auxiliary element 101 has energy directors 102 , 103 , such as ridges, tips or other protrusions. FIG. 20 shows that the first energy directors 102 at the interface to the first object 1 are more prominent than the second energy directors 103 at the interface to the second object 2 . In an embodiment it compensates for an asymmetry resulting from the fact that vibrations are coupled to the second object and not directly to the first object.

Figure 20 shows the regions around the energy directors where activation of the resin material dominates.

21 to 23 show top views on different auxiliary elements, thereby showing possible auxiliary element shapes. In general, it may be advantageous if in embodiments the auxiliary element has a different shape than a simple disk and thus the lateral surfaces are larger and thereby the interface to the resin is larger.

FIG. 24 again showing a cross-sectional view shows a guiding nipple 112 cooperating with a guiding hole 111 of the first object 1 in the auxiliary element 101 to define the exact position of the auxiliary element with respect to the first object. ) is shown.

In addition to or as an alternative to the thermoplastic material, the auxiliary element may also comprise other materials. In embodiments, for example, the auxiliary element may comprise an elastomeric material. Elastomer materials are usually not thermoplastic and nevertheless absorb vibrational energy and thereby heat up by internal friction.

29 shows an auxiliary element 101 in the form of a mesh, for example an elastomeric mesh. Such a mesh has the advantage that it can be placed between a first object and a second object for processing without requiring any precision in placement. For example, the auxiliary element 101 can be arranged as a strip along a glue line, for example from a corresponding nozzle, ie immediately before or after application of a glue bead by the same system. have.

The mesh has a free volume - i.e. the volume held between the strands 141 - see FIG. 30 - and can be chosen, for example, to represent at least 70% or at least 80% of the total volume. have.

The resin 3 is selectively applied over a large surface or in desired positions adapted for example to the shape of the first object and/or the second object, for example by means of a dispensing tool, as shown in FIG. 29 . can be distributed. If the resin is selectively disposed, it may be disposed across the mesh or optionally only also into the spaces 142 between the strands 141 .

29 embodiment of the first object and/or second object - of the second object of FIG. 29 - described with reference to FIGS. 27 and 28 and/or described with reference to FIGS. 17-19 (separated) It further has (optional) indentations 131 with (de-coupling) and/or defined thickness) functions.

FIG. 31 shows the principle of use on control foils 153 , 155 . These foils 153 , 155 are between the vibrating tool (sonotrode 6) and the second object 2 or between the first object 1 and the non-vibrating support 151 on which the assembly is placed for processing. or both.

31 shows both the first control foil 153 between the sonotrode 6 and the second object, and the second control foil 155 between the non-vibrating support 151 and the first object 1 . .

Such control foils may contain plastics that do not flow under the conditions applied during processing. An example of such a foil material is polytetrafluoroethylene (PTFE). A further suitable material is paper.

A control foil of the kind shown in FIG. 31 has been shown to significantly increase the efficiency in experiments, especially in the case of rigid non-vibrating supports.

Instead of the first control foil 153 and/or the second control foil 155 , a coating of the sonotrode 6 and/or the support 151 may be used, respectively.

FIG. 32 shows an arrangement wherein the first object 1 is at least partially thermoplastic and the second object 2 includes a distal perforation portion 161 that is installed to be drilled into the first object during processing.

In embodiments such as the embodiment of FIG. 32 , the at least one distal perforation portion 161 protrudes distally from the anchoring plate 31 or from another distally facing stop surface.

The distal perforation portion may for example comprise a tapering tip with or without an undercut ( FIG. 32 shows the undercut for the axial directions).

The perforated portion serves as a vibrational energy director during processing and locally liquefies the thermoplastic material penetrated by the perforated portion. Local absorption of vibrational energy leads to localized heating of the assembly around the interface between the perforated portion and the first object, whereby the resin is subjected to additional local activation as previously described.

The perforated portion provides rapid and significant stability, even when the entire resin does not cure for the reasons mentioned. This can be important in manufacturing processes where the assembly needs to have sufficient stability to move to the next manufacturing step.

As an alternative to having a perforated portion in places where the first object is at least partially thermoplastic and the second object is thermoplastic, this concept can be used in the following alternative configuration:

- the second object (in which the vibration is coupled in these embodiments) is at least partially thermoplastic and the first object comprises a perforated portion in places where the second object is thermoplastic,

- the first or second object is porous and capable of growing pores under hydrostatic pressure, the second or first object each comprising perforated portions of a thermoplastic material; Due to the mechanical vibrational energy, the thermoplastic liquefies and penetrates into the pores of each other object, whereby, after re-solidification, a embossed fit bond is achieved. It will also give rise to fast stable binding for major stability.

Fig. 33 shows the principle of using the resin 3 for embossed fit bonding in addition to adhesive bonding. To this end, the second and/or first object is provided with a structure that allows the resin to flow in such a way that an undercut is achieved after resolidification. In the embodiment of FIG. 33 , this structure is constituted by suitably positioned through-openings 33 of the second object 2 , through which the resin forms the button-like features 171 after resolidification back proximally. pressed to flow.

As shown in FIG. 34 , there may be a pattern of such openings 33 . Additionally or alternatively to the second object 2 , at least one of these openings may also be present in the first object 1 .

35 shows a sonotrode with a glue reservoir and optional pressure release holes 173 in the proximal portion of the second object. Where the opening(s) are present in the first object, the non-vibrating support (not shown in FIG. 35 ) may be provided with a counter structure with a glue reservoir and optional pressure release holes.

In particular embodiments, the flow-back discussed with reference to FIGS. 33-35 may optionally be applied to configurations according to the principles discussed with reference to FIGS. 11 and 12 .

Figure 36 shows a further option of the assembly in which the second object 2 is formed so as to achieve a quick and significant stability of the connection at the spot gluing points. However, in contrast to the embodiment of FIG. 32 , the second object does not perforate the first object.

The second object in FIG. 36 is a thermoplastic material having a plurality of protrusions 181 distally terminating, for example, at a tip or edge. When vibrations and urging forces are coupled into the second object 2 , which may be made of a hard material such as a metal or fiber reinforced composite, energy will be absorbed at the interface of these projections with the first object and of the projections 181 . This will lead to local melting. The protrusions will consequently deform ( FIG. 37 ) resulting in distance holding spacer structures 182 , and mechanical resistance to further movement of the second object 2 towards the first object 1 . will gradually increase. Also, due to energy absorption at the protrusions, the resin 3 is subjected to additional local activation around the protrusions leading to the localized curing regions 183, which ensures major stability spots even if the entire resin is not cured. .

FIG. 38 also shows in embodiments embodying the principle described with reference to FIGS. 36 and 37 , through openings 33 are optional, optionally having the functionality described with reference to FIGS. 33 to 35 .

Additionally or alternatively, it is optional to add a perforated portion 161 to the first object and/or to the second object, for example if the second object has a section of thermoplastic material.

Figure 39 shows a first type of protrusions, in addition to the first type of protrusions 181 having a tip or edge (in figure 39 the protrusions are shown elongate with a distal edge), also flattened. There may be distance maintaining protrusions 185 extending distally less distally. In FIG. 39 they are shown to have a star shape and distributed discretely over the surface. Other arrangements are possible, for example with discrete protrusions of the first type and/or with elongated distance keeping protrusions. In summary, the protrusions can be distributed to optimize all of the following:

- placement and distribution of locations where instantaneous activation of the resin occurs during processing (main stability points)

- Control of resin flow during the process

- Uniform mechanical support and distance definition during the process.

Claims (22)

A method of securing a second object to a first object, the method comprising:
- providing a first object comprising a first attachment surface;
- providing a second object, wherein one of the first object and the second object is at least partially made of a thermoplastic material;
- positioning the second object relative to the first object, with the resin between the first attachment surface and the second attachment surface of the second object;
- while the resin is in contact with the first attachment surface and the second attachment surface, causing mechanical vibrations to act on the second object or the first object or both, thereby activating the resin to cross-link and at least the flow of the thermoplastic material causing the portion to be flowable; and
- allowing the flowing part to re-solidify;
wherein, after allowing the flow portion to resolidify, the first object comprises:
a resin that, after crosslinking, secures the second object to the first object, and
a embossed fit engagement between at least one of the first object, the second object and the resin and the re-solidified flow portion
A method of fixing a second object to a first object, wherein the second object is fixed to the second object by the joint effect of According to claim 1,
A method of securing a second object to a first object, characterized in that the mechanical vibration is a longitudinal vibration. According to claim 1,
A method of securing a second object to a first object, characterized in that the mechanical vibration has a frequency between 15 kHz and 200 kHz. According to claim 1,
and causing the mechanical vibration to act comprises pressing the vibrating tool against a proximal coupling face of the second object. According to claim 1,
and pressing the second object and the first object against each other while causing mechanical vibration to act. According to claim 1,
A method of securing a second object to a first object, wherein the resin is in a flow state in the step of positioning the second object relative to the first object. According to claim 1,
A method of securing a second object to a first object, wherein one of the first object and the second object has a perforation provided for drilling into the thermoplastic material during the step of causing the mechanical vibration to act. According to claim 1,
A method of securing a second object to a first object, wherein the thermoplastic material comprises at least one energy director brought into contact with the first object or the second object during the method. According to claim 1,
one of the first object and the second object has at least one protrusion of a thermoplastic material;
disposing the second object relative to the first object, wherein the at least one protrusion is adjacent to the other of the first object and the second object;
In the step of causing at least a flowing portion of the thermoplastic material to be flowable, the protrusion is deformed. A method of securing a second object to a first object, the method comprising:
- providing a first object comprising a first attachment surface;
- providing a second object;
- positioning the second object relative to the first object, with the resin between the first attachment surface and the second attachment surface of the second object;
- while the resin is in contact with the first attachment surface and the second attachment surface, causing mechanical vibrations to act on the second object, whereby a part of the resin is activated to cross-link, while a further part of the resin is subjected to mechanical vibration not activated to cross-link by
including,
The method of fixing the second object to the first object, wherein the resin fixes the second object to the first object after cross-linking. 11. The method of claim 10,
wherein the second object has a seat portion and causing mechanical vibration to act upon causes mechanical vibration to act on the seat portion. 11. The method of claim 10,
and causing the mechanical vibration to act is repeated for a plurality of discrete positions of an assembly comprising the first object, the second object and the resin. 11. The method of claim 10,
A method of securing a second object to a first object, wherein the second object has a jagged portion, wherein the vibrating tool contacts the jagged portion in the step of causing mechanical vibration to act. 11. The method of claim 10,
A method of securing a second object to a first object, wherein the second object has a corrugation and, in causing mechanical vibration to act, the vibrating tool contacts the corrugation. 11. The method of claim 10,
further comprising providing an auxiliary element comprising a thermoplastic material capable of absorbing mechanical vibration;
In the step of causing the mechanical vibration to act, the auxiliary element is disposed between the first object and the second object and absorbs the mechanical vibration, thereby heating the resin in the vicinity of the auxiliary element. 2 How to fix the object. 16. The method of claim 15,
A method of securing a second object to a first object, wherein the auxiliary element comprises at least one energy director. 16. The method of claim 15,
A method of securing a second object to a first object, wherein the auxiliary element is a flexible planar structure. 18. The method of claim 17,
A method of securing a second object to a first object, wherein the flexible planar structure is a mesh. 16. The method of claim 15,
wherein in the step of positioning the second object relative to the first object, the auxiliary element functions as a distance holder between the first object and the second object, thereby defining the thickness of the resin. How to fix an object. A method of securing a second object to a first object by an adhesive connection, the method comprising:
- providing a first object comprising a first attachment surface;
- providing a second object;
- positioning the second object relative to the first object, with the resin between the first attachment surface and the second attachment surface of the second object;
- while the resin is in contact with the first attachment surface and the second attachment surface, causing mechanical vibrations to act on the second object or a plurality of discrete spots of the first object or both, thereby causing discrete parts of the resin activating to cross-link, while other portions of the resin are not cross-linked by mechanical vibration; and
- allowing different parts of the resin to cross-link while the second object is held in position relative to the first object by discrete parts of the resin, whereby the separate parts of the resin provide the principal stability of the adhesive connection. ensuring;
including,
A method of securing a second object to a first object, wherein the discrete portions and other portions of the resin, after cross-linking, secure the second object to the first object. 21. The method of claim 20,
further comprising the step of providing an auxiliary element comprising a thermoplastic material;
In the step of causing the mechanical vibration to act, the auxiliary element is disposed between the first object and the second object and absorbs the mechanical vibration, thereby heating the resin in the vicinity of the auxiliary element. 2 How to fix the object. 21. The method of claim 20,
A method of securing a second object to a first object, wherein the second object has a jagged portion, wherein the vibrating tool contacts the jagged portion in the step of causing mechanical vibration to act.

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